| 1. |
- Zhang, Zhi-Bin, et al.
(författare)
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Photo-Activated Interaction Between P3HT and Single-Walled Carbon Nanotubes Studied by Means of Field-Effect Response
- 2009
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Ingår i: IEEE Electron Device Letters. - 0741-3106 .- 1558-0563. ; 30:12, s. 1302-1304
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Tidskriftsartikel (refereegranskat)abstract
- It is shown in this letter that the field-effect electrical response of transistors with their channel made of networks of single-walled carbon nanotubes (SWNTs) embedded in a poly(3-hexylthiophene) (P3HT) matrix can be significantly altered by light illumination. The experimental results indicate a photo-activated electron transfer from P3HT selectively to the semiconducting SWNTs. This finding points to a potential optoelectronic application of such a field-effect device as a photo-triggered electronic switch.
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| 2. |
- Ackelid, Ulf, et al.
(författare)
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Ethanol sensitivity of palladium-gate metal-oxide-semiconductor structures
- 1986
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Ingår i: IEEE Electron Device Letters. - : Institute of Electrical and Electronics Engineers (IEEE). - 0741-3106 .- 1558-0563. ; 7:6, s. 353-355
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Tidskriftsartikel (refereegranskat)abstract
- Hydrogen-sensitive palladium-gate MOS structures heated above 150°C show sensitivity to ethanol vapor. The effect is probably due to catalytic dehydrogenation of adsorbed ethanol molecules on the surface of the palladium gate.
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| 3. |
- Andersson, Christer, 1982, et al.
(författare)
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A SiC Varactor With Large Effective Tuning Range for Microwave Power Applications
- 2011
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Ingår i: IEEE Electron Device Letters. - : Institute of Electrical and Electronics Engineers (IEEE). - 0741-3106 .- 1558-0563. ; 32:6, s. 788-790
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Tidskriftsartikel (refereegranskat)abstract
- SiC Schottky diode varactors have been fabricated for use in microwave power applications, specifically the dynamic load modulation of power amplifiers. A custom doping profile has been employed to spread the C(V) over a large bias voltage range, thereby increasing the effective tuning range under large voltage swing conditions. The small-signal tuning range is approximately six, and punch through is reached at a bias voltage of -60 V, while the breakdown voltage is on the order of -160 V. An interdigitated layout is utilized together with a self-aligned Schottky anode etch process to improve the Q-factor at 2 GHz, which is 20 at zero bias and approximately 160 at punch through.
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| 4. |
- Andersson, Kristoffer, 1976, et al.
(författare)
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Fabrication and characterization of field-plated buried-gate SiC MESFETs
- 2006
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Ingår i: IEEE Electron Device Letters. - 0741-3106 .- 1558-0563. ; 27:7, s. 573-575
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Tidskriftsartikel (refereegranskat)abstract
- Silicon carbide (SiC) MESFETs were fabricated using a standard SiC MESFET structure with the application of the "buried-channel" and field-plate (FP) techniques in the process. FPs combined with a buried-gate are shown to be favorable concerning output power density and power-added efficiency (PAE), due to higher breakdown voltage and decreased output conductance. A very high power density of 7.8 W/mm was measured on-wafer at 3 GHz for a two-finger 400-/spl mu/m gate periphery SiC MESFET. The PAE for this device was 70% at class AB bias. Two-tone measurements at 3 GHz /spl plusmn/ 100 kHz indicate an optimum FP length for high linearity operation.
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| 5. |
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| 6. |
- Asad, M., et al.
(författare)
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Graphene FET on Diamond for High-Frequency Electronics
- 2022
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Ingår i: IEEE Electron Device Letters. - : Institute of Electrical and Electronics Engineers (IEEE). - 0741-3106 .- 1558-0563. ; 43:2, s. 300-303
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Tidskriftsartikel (refereegranskat)abstract
- Transistors operating at high frequencies are the basic building blocks of millimeter-wave communication and sensor systems. The high charge-carrier mobility and saturation velocity in graphene can open way for ultra-fast field-effect transistors with a performance even better than what can be achieved with III-V-based semiconductors. However, the progress of high-speed graphene transistors has been hampered by fabrication issues, influence of adjacent materials, and self-heating effects. Here, we report on the improved performance of graphene field-effect transistors (GFETs) obtained by using a diamond substrate. An extrinsic maximum frequency of oscillation fmax of up to 54 GHz was obtained for a gate length of 500 nm. Furthermore, the high thermal conductivity of diamond provides an efficient heat-sink, and the relatively high optical phonon energy of diamond contributes to an increased charge-carrier saturation velocity in the graphene channel. Moreover, we show that GFETs on diamond exhibit excellent scaling behavior for different gate lengths. These results promise that the GFET-on-diamond technology has the potential of reaching sub-terahertz frequency performance.
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| 7. |
- Beuerle, Bernhard, et al.
(författare)
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Integrating InP MMICs and Silicon Micromachined Waveguides for sub-THz Systems
- 2023
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Ingår i: IEEE Electron Device Letters. - 0741-3106 .- 1558-0563. ; 44:10, s. 1800-1803
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Tidskriftsartikel (refereegranskat)abstract
- A novel co-designed transition from InP monolithic microwave integrated circuits to silicon micromachined waveguides is presented. The transition couples a microstrip line to a substrate waveguide sitting on top of a vertical waveguide. The silicon part of the transition consists of a top and a bottom chip, fabricated in a very low-loss silicon micromachined waveguide technology using silicon on insulator wafers. The transition has been designed, fabricated and characterized for 220-330 GHz in a back-to-back configuration. Measured insertion loss is 3-6 dB at 250-300 GHz, and return loss is in excess of 5 dB.
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| 8. |
- Beuerle, Bernhard, et al.
(författare)
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Integrating InP MMICs and Silicon Micromachined Waveguides for Sub-THz Systems
- 2023
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Ingår i: IEEE Electron Device Letters. - : Institute of Electrical and Electronics Engineers (IEEE). - 0741-3106 .- 1558-0563. ; 44:10, s. 1800-1803
-
Tidskriftsartikel (refereegranskat)abstract
- A novel co-designed transition from InP monolithic microwave integrated circuits to silicon micromachined waveguides is presented. The transition couples a microstrip line to a substrate waveguide sitting on top of a vertical waveguide. The silicon part of the transition consists of a top and a bottom chip, fabricated in a very low-loss silicon micromachined waveguide technology using silicon on insulator wafers. The transition has been designed, fabricated and characterized for 220 GHz to 330 GHz in a back-to-back configuration. Measured insertion loss is 3 dB to 6 dB at 250 GHz to 300 GHz , and return loss is in excess of 5 dB.
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| 9. |
- Bonmann, Marlene, 1988, et al.
(författare)
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Graphene field-effect transistors with high extrinsic fT and fmax
- 2019
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Ingår i: IEEE Electron Device Letters. - 0741-3106 .- 1558-0563. ; 40:1, s. 131-134
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Tidskriftsartikel (refereegranskat)abstract
- In this work, we report on the performance of graphene field-effect transistors (GFETs) in which the extrinsic transit frequency (fT) and maximum frequency of oscillation (fmax) showed improved scaling behavior with respect to the gate length (Lg). This improvement was achieved by the use of high-quality graphene in combination with successful optimization of the GFET technology, where extreme low source/drain contact resistances were obtained together with reduced parasitic pad capacitances. GFETs with gate lengths ranging from 0.5 μm to 2 μm have been characterized, and extrinsic fT and fmax frequencies of up to 34 GHz and 37 GHz, respectively, were obtained for GFETs with the shortest gate lengths. Simulations based on a small-signal equivalent circuit model are in good agreement with the measured data. Extrapolation predicts extrinsic fT and fmax values of approximately 100 GHz at Lg=50 nm. Further optimization of the GFET technology enables fmax values above 100 GHz, which is suitable for many millimeter wave applications.
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| 10. |
- Borg, Johan
(författare)
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Performance and spatial sensitivity variations of single photon avalanche diodes manufactured in an image sensor CMOS process
- 2015
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Ingår i: IEEE Electron Device Letters. - 0741-3106 .- 1558-0563. ; 36:11, s. 1118-1120
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Tidskriftsartikel (refereegranskat)abstract
- In this letter we present the results from a series of single-photon avalanche diode (SPAD) structures implemented in a commercial 0.18 μm CMOS process intended for CMOS image sensors. Variations without effect on the performance and variations that produced non-functional devices are described. Devices based on the P+/NWELL and deep-NWELL/P-EPI SPADs junctions were found to work well in this process. When biased for 10% QE the best 10 μm diameter P+/NWELL SPADs exhibited a DCR of about 1 kHz, whereas the DCR of the deep-NWELL/P-EPI SPADs was only 10 Hz under the same conditions. We also show that the former type exhibited local sensitivity variations within the SPADs ranging from a factor 4 at low excess voltage to 1.2 at an excess voltage of about 0.5 V. No significant sensitivity variations were found for the deep- NWELL/P-EPI SPADs, but they were found to exhibit significant sensitivity outside the central junction, contributing from 8.3 % at low excess voltage to approximately 70% at high excess voltage
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